Coal pulverizer and burner



1,614,314 Jan' 11 1927' T. E. MURRAY ET A1,

COAL PULVERIZER AND BURNR Filed March 19, 1924 1N VENTO/e E10/W15 E. MUR/wa 1; @a

0 y JJH/v ff. LA WEE/VCE.

s q I M A TTORNE y Patented Jan. 11, 1927.

UNITED STATES THOMAS E. MURRAY, or BROOKLYN, AND JOHN n. LAWRENCE, OF NEW YORK, N. Y.;

1,614,314. PATENT OFFICE.

SAID LAWRENCE ASSIGNOR T SAID MURRAY.

COAL PULVERIZER AND BURNER.

Application led March 19, 1924. Serial No. 700.214.

In certain previous applications of Thomas E. Murray there are described apparatus and methods for pulverizing coal and feeding it to a burner. The present invention provides a pulverizcr working on a s nnilar principle and utilizing a current of air first for breaking the coal, then for combustion.

Fig. lillustratcs in verticalsection an apparatus embodying the invention;

Fig. 2 is a similar view illust-rating a modification.

The walls land 2 and the floor 3 are parts yof a furnace in which the pulverlzed coal is to be burned. The tube 4 of the burner passes up through the floor and is closed by a top plate 5 forming withvthe suitably flared portions of the tube nozzles 6 through which the mixture of air and pulver-ized coal is injected into the furnace.

The coal is pulvcrized in a chamber 7 immediately below the nozzle. A plate 8 of cast iron or other hard material is located in the upper part of the breaking chamber. The coal is inipelled forcibly against the under face of the breaking plate by a jet or column of air forced under pressure through the tube 9 preferably constricted at the end to form a nozzle 10.

The coal is supplied from a hopper 11 and is led by a chute 12 to a feed tube 13 in which is a screw7- conveyor 14 the shaft of which is driven by any suitable means such as a gear 15 on its lower end. The conveyor carries the coal continuously to the air pipe 9. whence` it is projectedforcibly against the underside of the plate.

A portion of the coal is pulverized finely enough to be carried-along with the air to its outlets through the nozzles 6, and into the furnace where the mixture of coal and air is ignited and burned. The air current will naturally carry coal particles of different sizes, some of which will be coarserv than is customary in the use of pulverized coal. lilith this type of apparatus a considerable portion of the coal may be blown into the fire and ignited without having to be pulverized to the fineness which is requisite or customary where the coal is previously pulverized and is only fed through the nozzles by the air current. Ordinarily pow- `dered coal is about as fine as flour; whereas with this apparatus, we can use coal of which only about 1s so extremely fine, the remainder being considerably coarser.

The coarser particles of coal fall yto the bottom of the chamber 7 in a mass 16. The feed tube 13 is open at the sides at and 'pbelowthe end of the chute 12, so that part of the accumulation 16 enters thetube and is carried up to be again caught in the air current and thus subjected to repeated breaking operations. The quantity which is pulverized and carried through the burner is continuously replaced by the new coal arriving through the chute 12. The chute 12 and the openings in the feed tube 13 are kept substantially full: of coal so that there is little or no escape of air theretlnough. The usual draft in the furnace also ensures that the air shall escape entirely or chiefly by way of the nozzles.

Any desired number of such nozzles may be-arranged to project through the floor of the furnace at different points, or through the side walls by giving the proper direction to theburner tubes and nozzles. And each of such burners may have its own pulverizer and supply hopper, or a plurality of` burners may be connected with asingle pulverizer. The quantity of air ejected through the nozzle 10 may be exactly that calculated for the combustion of the coal. yratas described may be supplemented by devices for providing additional air or additional pulverized coal. Or where additional Or the appapulverized coal appears necessary it may be indicated at 18. `The bins will have the usual openings at the bottom with gates through which the coal can be fed as required to the hopper 1l. At the bottom of y the chut-e 12 the two grades of coal Will be thoroughly mixed and carried together intol the air jet and through the burner.

Though we have described with great particularity of detail a specific embodiment of our invention, yet it is not to be understood that the invention is restricted to the particular embodiment of our invention described. Various modifications thereof, in

detail and in the arrangement ofthe parts may be made by those skilled in the art without departure from the invention as defined inthe folowing claims.

What we claim is:

1. The combination with a burner of a pulverizer adjacent to and communicating at its outlet with theburner and comprising a breaking plate, means for directing a jet of air against the same and means for supplying coal to the jet of air to be thereby roken against the plate.

2. A casing, one end of which constitutes a burner, in combination with means for supplying coal to said casing, means for directing a jet of air to strike the coal supplied to the casing and to blow the coal and air through the burner and a breaker between the point of application of the jet to the coal and the point of combustion against which the coal is impelled and broken by impact as it is carried in the current of air.

8. A casing, one end of which constitutes a burner with a nozzle, in combination with a breaking plate in said chamber, means for directing a jet of air against the same and a conveyor for supplying coal to the'jet of air to be thereby broken against the plate, and carried with the air to the nozzle, the unbroken portion of the coal falling to the bottom of the casing and to the conveyor to be returned by the latter to the air jet and rebroken.

80 4. A casing, one end of which constitutes a burner with a nozzle in combination with abreakmg plate in said chamber, means for directmg a jet of air against the same and a conyeyor for supplying coal to the jet ofV air tobe thereby broken against the plate and carried with the air to thenozzle, the

unbroken portion of the coal falling to the bottom of the casing and to the conveyor to be returned by the latter to the air jet and rebroken, and a chute for supplying new coal to the conveyor.

5. The method of pulverizing coal and feeding it to a burner nozzle which consists f ticles of coal beyond said breaking surface v to a burner nozzle.

In witness whereof, we have hereunto signed our names.

THOMAS E. MURRAY. JOHN H. LAWRENCE. 

